User:Alice Harmon/Sandbox 5: Difference between revisions

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==Pyr/Pyl/RCAR family of ABA receptors==

~~[[Image:Abscisic acid.svg.png]]~~

~~[[Image:ABA model 2 med.jpg|right]]~~

~~Pyr~~/~~Pyl~~/RCAR ~~family~~ of ABA ~~receptors~~

{|

|[[Image:Abscisic acid.svg.png|thumb|]]

|[[Image:ABA model 2 med.jpg|right]]

|}

==ABA signaling pathway==

Abscisic acid (ABA;structure shown above at left) is a plant hormone that regulates seed dormancy and germination, stomatal closure, and responses to drought stress. As shown in the right figure, ABA binds to an ABA receptor (R)<ref>PMID:19893533</ref><ref>PMID:19407143</ref><ref>PMID:19407142</ref>. The activated receptor (R.ABA) binds to a protein phosphatase 2C (R.ABA-P), which was formerly in a complex with a SnRK2 protein kinase. The protein kinase is now free to be activated by autophosphorylation or phosphorylation by another protein kinase. Activation of SnRK2.6/OST1/SRK2E leads to phosphorylation of: 1) ion channels SLAC1<ref>PMID: 19955405</ref> and KAT1<ref>PMID: 19785574</ref> in guard cells and stomatal closure; 2) transcription factor ABI5<ref name = "Nakashima2009"/> in seeds/seedlings and dormancy/growth arrest; or 3) phosphorylation of transcription factor AREB/ABF <ref>PMID: 16446457</ref><ref name = "Fujii2007"/> in vegetative tissue and stress tolerance and growth regulation.

The ABA receptor family includes PYR1, PYR2, PYL1, PYL2, and RCAR. The ABA-responsive protein phosphatase 2Cs are in clade C and they include ABI1, ABI2, and HAB1. The ABA-activated protein kinases are in subclass III of SnRK2s and they include ==SnRK2.6/OST1/SRK2E==, and SNRK2.2/SRK2D and SnRK2.3/SRK2I

Structures in the figure are: R, apo PYR2, [[3kdh]]; R.ABA, PYR2.ABA, [[3kdi]]; K-P; SnRK2.6-HAB1, [[3ujg]]; R.ABA-P, PYR2.ABA-ABI2, [[3ujl]]; K, SnRK2.6,[[3uc4]].

The following Proteopedia pages

Abscisic acid is a plant hormone that signals water deficit, As shown in the figure, in unstimulated cells SnRK2.6/OST1/SRK2E (K) and a protein phosphatase 2C (P) are in a complex (K-P) in which the kinase is dephosphorylated and inactive<ref name ="Umezawa2009"> PMID:19805022 </ref><ref name ="Soon2012"> PMID:22116026 </ref>. The kinase and phosphatase are proposed to be tethered via the C-terminal sequence (dashed line) of the kinase<ref name ="Umezawa2009"/><ref name ="Soon2012"/><ref>PMID:16365038</ref>. When ABA levels in the cytosol rise, ABA binds to an ABA receptor (R)<ref>PMID:19893533</ref><ref>PMID:19407143</ref><ref>PMID:19407142</ref>. The activated receptor (R.ABA) binds to the protein phosphatase (R.ABA-P) and inactivates it. SnRK2.6/OST1/SRK2E, although still tethered to the phosphatase, is now free to be activated by autophosphorylation or phoshorylation by another protein kinase<ref>PMID:17103012</ref><ref>PMID:16980311</ref>.

==References==

@@ Line 1: / Line 1: @@
 ==Pyr/Pyl/RCAR family of ABA receptors==
-[[Image:Abscisic acid.svg.png]]
-[[Image:ABA model 2 med.jpg|right]]
-Pyr/Pyl/RCAR family of ABA receptors
+{|
+|[[Image:Abscisic acid.svg.png|thumb|]]
+|[[Image:ABA model 2 med.jpg|right]]
+|}
+==ABA signaling pathway==
+Abscisic acid (ABA;structure shown above at left) is a plant hormone that regulates seed dormancy and germination, stomatal closure, and responses to drought stress. As shown in the right figure, ABA binds to an ABA receptor (R)<ref>PMID:19893533</ref><ref>PMID:19407143</ref><ref>PMID:19407142</ref>. The activated receptor (R<sup>.</sup>ABA) binds to a protein phosphatase 2C (R<sup>.</sup>ABA-P), which was formerly in a complex with a SnRK2 protein kinase. The protein kinase is now free to be activated by autophosphorylation or phosphorylation by another protein kinase. Activation of SnRK2.6/OST1/SRK2E leads to phosphorylation of: 1) ion channels SLAC1<ref>PMID: 19955405</ref> and KAT1<ref>PMID: 19785574</ref> in guard cells and stomatal closure; 2)  transcription factor ABI5<ref name = "Nakashima2009"/> in seeds/seedlings and dormancy/growth arrest; or 3) phosphorylation of transcription factor AREB/ABF <ref>PMID: 16446457</ref><ref name = "Fujii2007"/> in vegetative tissue and stress tolerance and growth regulation.
+The ABA receptor family includes PYR1, PYR2, PYL1, PYL2, and RCAR. The ABA-responsive protein phosphatase 2Cs are in clade C and they include ABI1, ABI2, and HAB1. The ABA-activated protein kinases are in subclass III of SnRK2s and they include ==SnRK2.6/OST1/SRK2E==, and SNRK2.2/SRK2D and SnRK2.3/SRK2I
+Structures in the figure are: R, apo PYR2, [[3kdh]];  R<sup>.</sup>ABA, PYR2<sup>.</sup>ABA, [[3kdi]]; K-P; SnRK2.6-HAB1, [[3ujg]]; R<sup>.</sup>ABA-P, PYR2<sup>.</sup>ABA-ABI2, [[3ujl]]; K, SnRK2.6,[[3uc4]].
+The following Proteopedia pages
-Abscisic acid is a plant hormone that signals water deficit, As shown in the figure, in unstimulated cells SnRK2.6/OST1/SRK2E (K) and a protein phosphatase 2C (P) are in a complex (K-P) in which the kinase is dephosphorylated and inactive<ref name ="Umezawa2009"> PMID:19805022 </ref><ref name ="Soon2012"> PMID:22116026 </ref>. The kinase and phosphatase are proposed to be tethered via the C-terminal sequence (dashed line) of the kinase<ref name ="Umezawa2009"/><ref name ="Soon2012"/><ref>PMID:16365038</ref>. When ABA levels in the cytosol rise,  ABA binds to an ABA receptor (R)<ref>PMID:19893533</ref><ref>PMID:19407143</ref><ref>PMID:19407142</ref>. The activated receptor (R<sup>.</sup>ABA) binds to the protein phosphatase (R<sup>.</sup>ABA-P) and inactivates it. SnRK2.6/OST1/SRK2E, although still tethered to the phosphatase, is now free to be activated by autophosphorylation or phoshorylation by another protein kinase<ref>PMID:17103012</ref><ref>PMID:16980311</ref>.
 ==References==